As a method of producing a lower olefin such as ethylene, propylene, and butene, steam cracking of naphtha, and fluid catalytic cracking of vacuum gas oil have been heretofore generally carried out. In recent years a metathesis reaction using ethylene and 2-butene as raw materials, and a MTO (methanol to olefin) process using methanol and/or dimethyl ether as a raw material have been known.
Meanwhile, ethylene production by ethane cracking using ethane contained in natural gas as a raw material has been rapidly expanding due to recent price decline of natural gas. However, since ethane cracking scarcely yields hydrocarbons having a carbon number of 3 or more, such as propylene, butadiene, and butene, unlike steam cracking of naphtha, the shortage of hydrocarbons having a carbon number 3 or more, especially propylene and butadiene, has been surfacing.
Therefore, as a production method by which olefins having a carbon number of 3 or more, such as propylene, may be produced selectively, and the production amount of ethylene is suppressed, a MTO process using methanol and/or dimethyl ether synthesized from inexpensive coal or natural gas as a raw material has been attracting attention.
For example, as disclosed in Patent Document 1 and Non-Patent Literature 1, by using a catalyst containing a zeolite having a CON framework (Zeolite CIT-1) as an active ingredient, propylene and butene may be produced in high yield from methanol and/or dimethyl ether as a raw material, and further by-production of ethylene during propylene production may be suppressed. However, for industrial implementation, a catalyst having even higher performance is required currently.